Although the next election sometimes seems like a choice between root canal work and an operation for haemorrhoids, I do at least know which of the two parties I dislike more. The Blair-Brown thing is done and I will vote against it. But who, or what, I will vote for and why is much more difficult and at the centre of that question lies the puzzling nature of David Cameron's Conservative party, which seems at once familiar and unrecognisable

There is a lot that is interesting in his speeches, but just as you begin to think, well… maybe, something happens. The party makes a deal with the Sun and suddenly even the picture caption on the page three model becomes an attack on Gordon Brown, which is nearly enough to make me vote Labour.

Or the admirable Baroness Pauline Neville-Jones makes a statement about control orders, which she said "deny due process to the defendant, do not provide a reliable remedy to the security problem… and on top of all that cost hundreds of thousands of pounds. A Conservative government would review the morally objectionable and costly control order regime with a view, consistent with the security situation, to replacing it by the trial of suspects through the normal court system". It's difficult to disagree with that, but apparently Conservative MPs do. In the last three annual Commons votes on whether to continue the regime, they voted in favour once and abstained twice, leaving the Liberal Democrats to carry on the fight. So at the minimum it seems rather eccentric for the baroness to pretend otherwise.

The same was true when it came to secret inquests. Having denounced Jack Straw's plan to increase the power of the state by allowing ministers to call for a closed hearing, Conservative peers abstained when the bill returned to the Lords last week. The villainous Jack Straw got his way again and it seems likely that for the first time since 1194, when the office of coroner was formally established, an inquest may be held in secret.

This may not seem very important compared to the great issues of tax and spending, global warming and an ageing population, but it's worth noting that the Tories are suddenly displaying the slipperiness of a governing party. During an interview with John Humphrys on the Today programme last week, it was striking how Cameron seemed just like a prime minister defending his record. To be fair, this wasn't his fault, yet it is curious how the Conservatives have somehow been fast-forwarded, past the I-have-a-dream bit, to a defensive stance that implies they are already in power. That's a measure of the fatigue with the Brown government but also of the scale of disappointment with a Labour administration that was deeply flawed yet was never less than certain of its own virtue.

We want more humility from our leaders these days. We are less trusting and, judging by Cameron's reception on the Mumsnet site last week, people are wary of falling for another family man with plausible good looks.

Cameron has not been allowed to forget the "cast-iron guarantee" for a referendum on the Lisbon treaty and the legalistic but unconvincing excuse that the treaty is no longer a treaty but a piece of European law. And few people believe the alliance in Europe with right-wingers serves the party's purpose or that it was fair to expel Edward McMillan-Scott MEP from the party after he challenged the dubious Polish MEP Michal Kaminski. The reaction seemed a bit thuggish and panicky, and it makes you wonder what the party would be like in power. Is this the actual nature of the Conservatives or are they just trying to seem tough and decisive? It is difficult to know.

Reading Cameron's recent speeches, I find there are moments when I genuinely want to shout, like a southern Baptist: "Praise the Lord." In May, he spoke about "the reason why so many innocent citizens now mistrust and fear the police and why so many people feel that the state is their enemy, not their ally". This was important and he followed it with an attack on cultural authoritarianism, which wasn't quoted much because of its rhetorical style. "No trust, no discretion, no judgment. Just the grey, monotonous, maddening refrains of life in Britain. 'I'm sorry, I don't make the rules.' 'It's for your own safety.' 'It's for child protection, I'm afraid.'"

At another point, he talked about reforming Parliament to increase transparency and hold the executive to account, which doesn't quite square with the Conservative behaviour on control orders and secret inquests. Still, it is good to see him on the record, particularly as his friends, rather than his colleagues, say he believes it all.

There is much else that attempts to plumb the mysteries of a particular British social malaise. The headlines talk about the post-bureaucratic age, big society replacing the big state, localism and personal responsibility. In other words, classic centre ground stuff which, to be honest, New Labour might easily have dreamt up if the party hadn't been filled with an unholy contempt for the public and staffed by some arrogant statists.

The Tory analysis says the big state is inimical to freedom and individual responsibility but, crucially, also to equality. It must baffle the government that, after all the investment of the last 12 years, the gap between rich and poor has widened, that poor, white, working-class kids are now the worst performers at school. In the Hugo Young lecture earlier this month, Cameron referred to the authors of a book of the moment, Spirit Level. "They show that per capita GDP is much less significant for a country's life expectancy, crime levels, literacy and health than the size of the gap between the richest and poorest." That a Conservative leader is saying these things tells you that there is only one place to be in British politics and that is the centre ground, yet I remain a little hazy about how the gap will be closed by the Tories, particularly in a long period of spending cuts, and this is perhaps because the Tories are hazy too.

I also have difficulties with Cameron's phrase "broken society", because it ignores so much that is good and tolerant about British society in favour of an analysis that concentrates on the negative. That may be the way politics works but it is wrong to talk of rising crime when, actually, reported crime is 42% down since 1995. It leads you back to the punitive, interfering philosophy of New Labour and you end up locking up more and more people at great expense and without reducing reoffending rates.

This mania about crime and disorder – led by papers like the Sun, which were granted far too much access to Labour's policy making – has resulted in the prison population rising from 60,000 to about 84,000 since 1997. Labour's policy thrust showed no interest in the communities producing offenders and saw courts being relocated from city centres to the periphery of cities. As a report of the Commission for English Prisons Today says: "This process, combined with the increasing use of imprisonment, has further alienated communities from the working of criminal justice."

That was all part of Labour's madness and you don't have to be a Conservative to see it. What I yearn for is cool, rational and transparent government that addresses big problems without suffocating individual potential and liberty. There is a lot of sense in Cameron's thinking, but also in what the Liberal Democrats are saying and at least they did not abstain when some important issues came along.